Biology subjects

Perez-Perez, J. M.

Publications and source records attributed to Perez-Perez, J. M..

3 recordsLinked to original sources

bioRxiv2022

Mapping of the Classical Mutation rosette Highlights a Role for Calcium in Wound-induced Rooting

Removal of the root system induces the formation of new roots from the remaining shoot. This process is primarily controlled by the phytohormone auxin which interacts with other signals in a yet unresolved manner. Here, we study the classical tomato mutation rosette (ro) which lacks shoot-borne roots. ro plants were severely inhibited in the formation of wound-induced roots and have reduced rates of auxin transport. We mapped ro to the tomato ortholog of the Arabidopsis thaliana BIG and the mammalians UBR4/p600. RO/BIG is a large protein of unknown biochemical function. In A. thaliana, BIG was implicated in the regulation of auxin transport and calcium homeostasis. We show that exogenous calcium inhibits wound-induced root formation in both tomato and A. thaliana ro/big mutants. Exogenous calcium antagonized the root-promoting effects of the auxin IAA, but not of 2,4-D, an auxin analog that is not recognized by the polar transport machinery, and accumulation of the auxin transporter PIN1 was sensitive to calcium levels in the ro/big mutants. Consistent with a role for calcium in mediating auxin transport, both ro/big mutants and calcium-treated wild-type plants were hypersensitive to treatment with polar auxin transport inhibitors. Subcellular localization of BIG suggests that like its mammalian ortholog, it is associated with the endoplasmic reticulum (ER). Analysis of subcellular morphology revealed that ro/big mutants exhibited disruption in cytoplasmic streaming. We suggest that RO/BIG maintain auxin flow by stabilizing PIN membrane localization, possibly by attenuating the inhibitory effect of Ca2+ on cytoplasmic streaming.

plant biology↗

bioRxiv2021

Methods for in situ quantitative root biology

When dealing with plant roots, a multi-scale description of the functional root structure is needed. Since the beginning of XXI century, new devices like laser confocal microscopes have been accessible for coarse root structure measurements, including 3D reconstruction. Most researchers are familiar with using simple 2D geometry visualization that does not allow quantitatively determination of key morphological features from an organ-like perspective. We provide here a detailed description of the quantitative methods available for three-dimensional (3D) analysis of root features at single cell resolution, including root asymmetry, lateral root analysis, xylem and phloem structure, cell cycle kinetics, and chromatin determination. Quantitative maps of the distal and proximal root meristems are shown for different species, including Arabidopsis thaliana, Nicotiana tabacum and Medicago sativa. A 3D analysis of the primary root tip showed divergence in chromatin organization and cell volume distribution between cell types and precisely mapped root zonation for each cell file. Detailed protocols are also provided. Possible pitfalls in the usage of the marker lines are discussed. Therefore, researchers who need to improve their quantitative root biology portfolio can use them as a reference.

plant biology↗

bioRxiv2021

Tissue-specific metabolic reprogramming during wound induced de novo organ formation in tomato hypocotyl explants

O_LIPlants have remarkable regenerative capacity, which allows them to survive tissue damaging after biotic and abiotic stress. Some of the key transcription factors and the hormone crosstalk involved in wound-induced organ regeneration have been extensively studied in the model plant Arabidopsis thaliana. However, little is known about the role of metabolism in wound-induced organ regeneration. C_LIO_LIHere, we performed detailed transcriptome analysis and targeted metabolomics approach during de novo organ formation in tomato hypocotyl explants and found tissue-specific metabolic differences and divergent developmental pathways after wounding. C_LIO_LIOur results indicate that callus growth in the apical region of the hypocotyl depends on a specific metabolic switch involving the upregulation of the photorespiratory pathway and the differential regulation of photosynthesis-related genes and of the gluconeogenesis pathway. C_LIO_LIThe endogenous pattern of ROS accumulation in the apical and basal region of the hypocotyl during the time-course were dynamically regulated, and contributed to tissue-specific wound-induced regeneration. C_LIO_LIOur findings provide a useful resource for further investigation on the molecular mechanisms involved in wound-induced organ formation in a crop species such as tomato. C_LI One-sentence SummaryMetabolic switch during wound-induced regeneration

plant biology↗